Electrical control means for rotary franking machines



W. MULLER July 13, 1954 ELECTRICAL CONTROL MEANS FOR ROTARYFRANKINGMACHINES Filed Oct. gn, 1952 2 Sheets-Sheet 1 W. MULLER July 13, 1954ELECTRICAL CONTROL MEANS FOR ROTARY FRANKING MACHINES 2 Sheets-Sheet 2Filed Oct. 1'7, 1952 w W Nw Q mw o Patentecl July 13, 1954 ELECTRICALCONTROL MEANS FOR- ROTARY FRANKING MACHINES Wilhelm Miiller, Frankfurtam Main, Germany,

assignor to Telefonbau und Normalzeit Gesellschaft mit beschrankterHaftung, Frankfurt am Main, Germany, a joint-stock company of GermanyApplication October 17, 1952, Serial No. 315,301

9 Claims.

The present invention relates to franking machines which are used forprinting a stamp replacing an adhesive stamp on letters, postcards, orother matter to be forwarded by mail.

1 In one type of prior art franking machines a stamp is printed directlyon the matter to be forwarded by mail. In another prior art frankingmachines stamps are being printed on a strip of paper or tape drawn froma storage roller whereupon, the strip or tape is subdivided by a cuttingdevice of the machine into individual lengths usable for frankingnewspapers, periodical and the like. It has also been suggested to adaptfranking machines for printing stamps directly on letters and the likemail for successive printing of stamps on tape. In one type of theselast referred-to machines the end of a tape is being moved forward by aprinting roller out of the initial printing position and fed to acutting device which cut off the printed end from the tape, whereuponthe unused end thereof is returned to the printing position. In analternative arrangement, a length of tape to be printed is being cut offand the cut-off length then fed to the printing roller. has an automaticcontrol of the printing roller responsive to the feed of the matter tobe printed and can also be employed for printing on paper tape. In botharrangements, a guide for the paper tape, a feeding device therefor anda cutting device are combined to form a structural unit which can beadded at will to the frame of the franking machine. With botharrangements it is however only possible to obtain the intended mode ofoperation by interfering with the driving mechanism of the frankingmachine and by adding auxiliary steps of operation.

It is an object of the invention to provide a simple franking machinewhich is capable of being used selectively for printing stamps either onindividual matter to be forwarded by mail, such as letters, orpostcards, or on paper strips or tape.

Another object of the invention is to provide a franking machine forsuch selective use without the necessity of interfering with the drivingmechanism of the machine on change from one mode of use to the other.

A further object of the invention is to provide a franking machine forprinting stamps on strips of paper and cutting the strips, wherein thestrips are always fed through the machine in the same direction.

Still another object of the invention is to modify a franking machinewith an automatic control of its printing roller responsive to the feedThis type of franking machine of the matter to be printed in a simplemanner in such a way that it is possible to feed a strip of paper drawnfrom a storage device into and through the machine without subdividingthe strip, without changing the direction of the movement thereof, andwith a constant but pre-settable speed, and thus to print successivelyspaced stamps on such strips.

These and other objects and advantages of the invention will becomeapparent to those skilled in the art from the following detaileddescription of an embodiment of the invention, when read in conjunctionwith the appended drawings, which are given by way of example only andin which:

Fig. 1 is a perspective View of a franking machine embodying theinvention;

Fig. 2 is a front elevational view of the same machine as shown in Fig.1 and Fig. 3 is an electric circuit diagram of the machine of Figs. 1and 2.

According to the invention, an electric main contactor operable by anelectric motor for driving a printing roller at regular time intervalscorresponding to the sequence of prints on a paper strip is provided inan electric control circuit for the printing roller in series with anauxiliary contactor which is kept closed by a paper strip While thestrip is being fed through the machine, whereby to enable stamps to besuccessively printed on the strip, each print being effected by theclosing of the main contactor. The auxiliary contactor operable by thepaper strip only prepares the control circuit for the printing roller,while the main contactor operable by the electric motor closes the saidcontrol circuit at regular time intervals. The auxiliary contactor iskept closed only during the feed of the strip and thus breaks thecontrol circuit when the feed of the strip is terminated. The auxiliarycontactor also breaks the control circuit and thereby prevents a furtheroperation of the printing roller when the paper strip becomesaccidentally torn. The electrically controlled mechanism of the frankingmachine is inexpensive and may easily be added to an existing frankingmachine.

Preferably, a further contactor is provided in the electric controlcircuit and is controllable by a counting device for counting the numberof stamps printed on the strip in such a manner that said furthercontactor is opened when a number of prints which is predetermined bythe setting of the counting device have been effected.

In order to enable stamps to be printed on pieces of tape of differentlengths, a plurality of main contactors may be provided which areoperable by the electric motor at regular time intervals difierent foreach contactor, one of the said main contactors being insertable at willinto the electric control circuit for the printing roller. Preferably anelectric change-over switch is provided in the control circuit for theprinting roller which bridges the main contactor or contactors operableby the electric motor at regular time intervals and also the furthercontactor, if any, in its position for directly franking letters. In itsother position or positions intended for printing stamps on paper tapewhich positions correspond to the number of main contactors thischange-over switch inserts the main contactor or one of the maincontactors, and also the further contactor, if any, into the electriccontrol circuit;

The drawings show, a manually operable stamping device 2 removablyattached to a base I of a franking machine. When the stamping device 2has been detached, it may be removed from the frame I and may be usedmanually for printing stamps on any suitable object. For mechanicallyoperating the stamping device 2 when attached to the base I of thefranking machine, an electric motor 3 is provided which islikewise-mounted on the base I.

In front of the inlet of the franking machine a removable table 5 isprovided for supporting letters or postcards to be franked. When it isintended to successively print stamps on a strip of paper or tape, thetable 5 is replaced by a bracket 6 for a paper roll 1. At the outlet ofthe franking machine, a removable cutting device 8 is provided forcutting the stamped strip of paper at regular intervals. Between theinlet of the franking machine and thestamping device 2, a switchingmechanism 9 is provided which is adapted tobe operated by the matter tobe franked. The electric motor 3 drives one of a pair of conveyerrollers l l by means of a suitable gear, a conveyer belt 4 being placedaround and being driven by said rollers. Counter-pressure rollers l3press-against conveyer belt 4. The electric motor 3 also drives a firstmember l5 of a dog-clutch by means of a chain l4, and a camshaft IT bymeans of a reduction gear I6. Printing roller 13 of the stamping device2 is mounted adjacent to conveyer belt 4. The printing roller !8 isoperatively connected to a shaft 25 carrying a'second member of thedog-clutch by means of an intermediate gear ill. The second member ofthe dog-clutch is urged by a spring (not shown) in the direction towardsthe first member E5 of the dog-clutch, but is normally prevented frommoving in this direction by a locking lever '24 controlled by anarmature 22 of an electromagnet 23. The locking lever 24 bears-against aprojection-25 of a disc keyed to the shaft 2i. Matter to be stamped andplaced onto the conveyer belt 4 passes a tiltable lever 26 arranged infront of the stamping device 2. A permanent magnet 28 is arrangedadjacent a mercury switch 21, and is mechanically tied to the tiltablelever 26. Within the mercury switch 2?, a solid contact member 3| isfixed to a resiliently supported iron arm-29 arranged opposite a cup 30containing mercury, the solid contact member 3| being normally liftedout of the mercury in the cup 30 under the action of the permanentmagnet 28 on the iron arm 23. When matter to be stamped and placed ontothe conveyer belt 4 reaches the tiltable lever 25, the same rotates thepermanent magnet 28 to such' an extent away from the mercury switch '21that the solid contact member 3| drops into the mercury in thecup 30owing to the weight of the iron arm 23, whereby the mercury switch 21 isclosed. The cam-shaft ll carries three cams 32, 33 and 34, of which thecam 32 has one projection, the cam 33 has two projections arrangeddiametrically opposite to each other, and the cam 34' has threeprojections equally distributed along the periphery of the cam. Each ofthe cams 32, 33 and,34 cooperates with one of three contactors 35, 36and 3'! formed by sets of contact springs controllable by thecorresponding projection or projections of the cams. When shaft I! isrotated the projections on cams 32, 33'and 34 engage the contact springsof contacts 35, 36 and 3'! and efiect contact between them.

The shaft 2| carries a cam 38 acting on a rotatable lever 3'9'of'asubtracting counting device 40; A desired number of stamps to be printedmay be predetermined by means of rotatable nobs 4'l provided on saidcounting device. The predetermined number of stamps appears behind thewindows 42 of counting device 40. On each complete revolution of'the cam38, the predetermined number' is reduced by one digit. The countingdevice 40 comprises a further contactor 43 which is kept closed as longas the number shown by the counting device 40 is difierent from zero,and the further contactor 43 is opened when the counting device is downto and indicates zero.

A two-wire line 46 for energizing theelectric motor 3 terminates in aplug45' and includes a double-pole switch 41 andthe exciting orenergizing coil 48 of the electromagnet 23 and the switching mechanism 3forming an auxiliary contactor arranged inseries with the exciting coil43. The above circuit includes four'terminals 5i, 52, 53 and 54 of atwo-stage change-over switch 50. Mechanism 9 is either directlyconnected to the terminal 5t of switch 50* or across'one of the maincontactors 35; 3B; 31, controlled by the cams 32, 33, and 34to oneof'the terminals 52, 53, and 54 of switch 50. Furthermore, the circuitincludesterminals 55, 55, 5'Iand 58 of the second stage of change-overswitch 55. The portion of switch 50 shown at the right of Fig. 3 may,either be directly connected to the terminal 55, or across the furthercontactor 43 to the terminals 53, 51' and 58; The second stage of thechange-over switch 50'shown at the left of Fig. 3 isconnected over afuse 59 to the double-pole switch 41. The driving electric motor 3 isshunted across the two wires of the energizing line or, tobemorespecific, is branched off between one pole of the double-poleswitch 4'! and the exciting or energizing coil48of theelectromagnet 23.Motor 3 is connected totheswitching lever of the change-over switch50-which co-operates with I the terminals 5i to 54. When the twoswitching levers of the change-over switch 50 are placed on terminals 5!and 55, respectively, as shown in Fig. 3, the" contactors 35, 35and31controlledrespectively by the cams 32, 33 and 34, as well asthefurther contactor 43 are bridged-or shunted out. Change-over switch 53-is placed in this positi'on'which will briefly be referred to by theabbreviatedterm letter when it is intended to print directlyonletters'or postcards. However, when" the switching levers of thechange-over switch Ell-are positioned on one of the pairs ofterminals52; 56; or 53', 51-; or 54, 58, then, in each caseyone of the contactors35, 36, and 3! controlled, respectively, by the'cams 32; 33 and 34,andalso the further contactor 43, controlled by the-counting device'40-, are efiective.

Since the cams 32, 33 and 34 are driven by the electric motor 3 with aconstant speed, the contactors 35, 3S, and 3'! are periodically closedand opened but each at different time intervals. Now, depending on theposition of the change-over switch 59, that is to say depending on whichone of the contactors 35, 36 and 37 has been rendered eifective in eachcase, the electric control circuit is periodically closed and opened butthe time intervals are diii'erent for each of the three contactors. Theterminals 52, 53 and 54; and 56, 51 and 58 are rendered effective whenit is intended to print stamps onto a paper strip or tape. Thecorresponding positions in which the change-over switch 58 is placedwhen it is intended to print on a paper will be referred to by theabbreviation strip.

When the double-pole switch 4.1 is closed after insertion of the plug 45into a corresponding socket of the main supply, the electric motor 3 isstarted and drives the conveyer belt 4 as well as the chain Hi. When thechange-over switch 55 is in position letter, the electric circuit forthe electromagnet 23 operating the dog-clutch is closed each time aletter passes the tiltable lever 26 of the switching mechanism 9,causing the locking lever 24 to release the printing roller l8 while itis coupled to the electric motor 3 by the dog-clutch to perform onerevolution and to print a stamp on to the letter carried through themachine by the conveyer belt 4. The time interval between the operationof the tiltable lever 26 by a letter and the release of the iron arm 29is so selected that the letter to be franked reaches the printing rollerl8 during this interval. Each franking print is counted by the countingdevice 40 of the stamping device 2. When the changeover switch 55 isbrought into one of the positions strip, then the auxiliary contactorformed by the switching mechanism 9 remains closed during the passage ofa strip through the franking machine inserted into it. The electriccircuit prepared by switching mechanism 9 is closed by one of the maincontactors 35, 36 and 3 7 operated by the electric motor 3 at regularintervals of time whereby on each closing of the respective contactorthe electromagnetically operated dogclutch causes one single revolutionof the printing drum which performs one print on the strip. The numberof prints on the strip is being counted by the counting device 40. Thecutting device 3 arranged at the outlet of the franking machine andoperated by the armature 22 of the electromagnet 23 cuts ofi a desiredlength of the strip after each print. When a predetermined number ofprints have been made on a tape, the electric control circuit isinterrupted by the further contactor 43 of the counting device 40. Thecutting device 8 comprises a sleeve 69 fixed on a frame or casing of thefranking machine. Sleeve 68 has slots 6| and 62 of different width atthe front and the rear, respectively. A roller 63 is rotatably mountedwithin the sleeve 6:] and has a conical slot 64 extending through it.The limiting edges of the slot 54 at the narrowest region thereofoperate as cutting edges. In its initial position, the conical slot 85registers with the slot 52 at the rear of the sleeve 60. The roller 63is tied mechanically to the armature 22 of the electromagnet 23 in sucha manner that each time the armature 22 is attracted, the roller 63performs a limited rotation. A paper strip 65 threaded through the slotsof the sleeve 60 and of the roller 63 is cut off by the rotationalmovement of the roller 63 caused on each excitation or energization ofthe electromagnet 23. After the cutting process has been terminated, theconical slot 64 of the roller 63 guides the paper accumulated thereinduring a cutting process towards the slot 52 of the sleeve fill. Thecutting device 8 as well as the table 5 and the bracket 6 for holdingthe paper roll 1 may be connected to the frame or casing of the frankingmachine by a clamp lock which is easily releasable.

The spacing of successive prints on the strip or tape depends on thenumber of projections on the cams 32, 33, 34 for operating the maincontactors 85, 3t, 37, respectively, which are rendered efiective in thestrip positions of the change-over switch 50. When the number ofprojections is increased, the electromagnet 23 operates the dogclutch atcorrespondingly shorter time intervals, whereby the strip or taperunning through the machine is provided with stamp prints at shorterdistances. According to the desired length of the cut-off pieces of thestrip, the cams 32, 33 and 34 may be exchangeable against others havinggreater numbers of projections. If the paper strip should tear duringthe operation of the device, the switching mechanism 9 operating themercury switch 21 relapses, whereby the solid contact member 3!, owingto the iron arm 29 being now attracted by the permanent magnet 28, islifted from the mercury cup 30 opening the mercury switch. Thereby theelectromagnet 23 for operating'the dog-clutch is disconnected so thatthe printing roller i8 is rendered inoperative. The printed lengths cutoff from the paper strip or tape may subsequently be fed through anaddressing machine providing the lengths of the paper strip withaddresses.

I claim:

1. A franking machine comprising means for feeding matter to be frankedthrough said machine, a printing roller for printing a franking stamp onsuch matter, a drive, a clutch for coupling said drive to said printingroller, an electric control circuit, means in said circuit for operatingsaid clutch to cause said printing roller to perform a revolution whensaid control circuit is closed, an electric main contactor in saidcircuit, said main contactor being operable by said drive to make andbreak said control circuit at regular intervals of time to cause theprinting roller to print franking stamps at regular distances on tapefed through said machine, and an electric auxiliary contactor arrangedin said control circuit in series with said main contactor, and operableby the matter to be printed while fed through said machine to preventcontinued printing when the feed of the tape is interrupted, contactormaking and breaking the control circuit at regular time intervals tocause the printing roller to print franking stamps at regular distanceson to the strip, the auxiliary contact preventing the printing when thefeed of the strip is interrupted.

2. A franking machine as claimed in claim 1, wherein a plurality of maincontactors are provided in the electric control circuit, the said maincontactors being all operable by the drive to make and break saidcontrol circuit at regular time intervals of different lengths fordifierent main contactors, means being provided for alternativelyrendering one of the main contactors effective, whereby to alter thedistances between stamps printed on a strip in dependence on the maincontactor rendered efiective.

3. A franking machine as claimed in claim 2, wherein a plurality of camsare inserted between accents andcomprising' a reduction gear between thedrive and the cams. V

5. A-franl ing machine as claimed in claim 2, and comprising a changeover switch in the electrio control circuit which in one positionbridges the main contactors-and the further contactor to render'the sameineffective for printing stamps on the separate matters, and in each ofits other positions, the number of which corersponds to the plurality ofmain contactors, renders one of the main contactors and the furthercontactor effec-' tive'for printing stamps on to-a' strip of material.

6. A franking machine as claimed in claim 2,

and comprising a frame housing the drive, the

printing roller forming part of a manually operable stamping devicereleasably coupled to said drive, the electric control circuitforsaiddrive comprising the auxiliary contactor, the plurality of maincontactors and the further contactor.

7. A postage printing machine comprising a tape feeding device, aprinting roller suppliedwith tape from said feeding device, motor meansfor operating said printing roller, a clutch for selectively couplingand uncoupling said motor means and said printing roller; an electriccontrol circuit, a magnetic means energizable by the flow of current insaid circuit to operate said clutch to couple said motor means and saidprint ing roller, a first switching device arranged in said circuitoperable by said motor means to effect periodic opening and closingoperations of said circuit tocause periodic operation of said printingroller to make a plurality of equidistant imprints on said tape, asecond switching device arranged in said circuit in series with saidfirst switching device, and means under the control of said tape whenfed from said feeding device to said printing roller for controllingsaid second switching device to interrupt said circuit to stop theoperation of said printing roller upon interruption of the feed of saidtape.

8. A postage printing machine comprising a tape feeding device, aprinting roller supplied with tape from said feeding device, motor meansfor operating said printing roller, an automatic clutch for selectivelycoupling and uncoupling said motor means and said printing roller, anelectric control circuit, an electroinagnet energizable by the flow ofcurrent in said circuit, a linkage operated by said electromagnet tooperate said automatic clutch to couple said motor means and saidprinting roller, a first switching device arranged in said circuit andoperable by said motor means, said first switching device comprising aplurality of pairs of contacts each operabie to effect a differentnumber of periodic opening and closing operations of said circuit in agiven interval of time to cause periodic operation of said printingroller to make a plurality of equidistant imprints on said tape, aplurality of different cam means operated by said motor means eacheffecting relative movement of one of said plurality of pairs ofcontacts to cause said periodic opening and closing operations of saidcircuit, a second switching device arranged in said circuit in serieswith said first switching device, and means under the control 01'' saidtape when fed from said feeding device to said printing roller forcontrolling said second switching device to interrupt said circuit tostop the operation of said printing roller upon interruption of the feedof said tape.

9. A iranking machine as claimed in claim 1 comprising a subtractingcounting device adapted to be manually pre-set on a pre-determinednumber, means controlled in accordance with the rotary motion of saidprinting roiler to subtract the number of stamps printed by saidprinting roller from the predeterminednumber manually pre-set in said,counting device, a further contactor arranged in the electric controlcircuit for maintaining said circuit closed as long as the differencedetermined by said counting device difiers from zero, and meanscontrolled by said counting device for opening said further contactor oncompletion of the pre-set number of prints to break said control circuitto preclude continued printing by said printing rolier upon completionof the pre-set number of prints.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,238,359 Copeland et a1 Apr. 5, 1941 2,350,703 Ryan et a1June 6, 1944 2,518,011 Hoppe Aug. 8, 1950

